Problem Solving
2–15
Figure 2–4:
Problem Solving the FDDI Interface
PHY_n on
(solid red)
?
Yes
PHY_n
off
?
PHY_n
blinking
red
?
Yes
Yes
Normal condition,
end problem solving.
Loopback
switch
enabled
?
No
Yes
Bad LED. Replace
FI module.
PHY_n
blinking
green
?
PHY_n
still blinking
green
?
Loopback
Test
Yes
No
No
FI_BAD
on
?
A
B
Loopback
connector
installed
?
Install loopback
connector.
No
Yes
Yes
Wait 1
minute.
No
No
No
Check
connection.
Yes
No
No
Yes
A
PHY_n
solid
green
?
Yes
No
On a DAS, check for illegal topology (Appendix B).
On a SAS, run loopback test. If OK, check cable. If
cable is OK, replace FI module, and if necessary,
AP module.
Cycle power and wait
for self-test to complete.
PHY_n
still blinking
green
?
Replace FI board.
LKG–5116–91I
